Method and apparatus for controlling uplink power in wireless communication system

1. A method for operating a user equipment (UE) in a wireless communication system, the method comprising:

establishing a first link with a first base station (BS) and a second link with a second BS, the first BS and the second BS configured in a dual connectivity for the UE; and

in response to identifying that a power headroom report (PHR) trigger event associated with the first BS occurs, transmitting a dual connectivity PHR to the second BS,

wherein the dual connectivity PHR comprises a first power headroom (PH) for a cell provided by the first BS and a second PH for a cell provided by the second BS.

2. The method of claim 1 , wherein the dual connectivity PHR is provided based on a media access control (MAC) control element (CE).

3. The method of claim 1 , further comprising:

receiving, from one of the first BS and the second BS, a message comprising:

first control information related to the dual connectivity PHR for the first BS, and

second control information related to the dual connectivity PHR for the second BS.

4. The method of claim 3 ,

wherein the first control information comprises a periodic timer, a prohibit timer, and a threshold for a path loss change for the first BS, and

wherein the second control information comprises a periodic timer, a prohibit timer, and a threshold for a path loss change for the second BS.

5. The method of claim 1 , wherein the dual connectivity PHR is transmitted through an uplink resource allocated by the second BS.

6. The method of claim 1 , further comprising:

identifying that the PHR trigger event occurs based on at least one of a path loss change, a maximum power reduction (MPR) change, secondary cell (S cell) activation, Scell addition, and a power back off change.

7. The method of claim 1 , further comprising:

in response to identifying that the PHR trigger event occurs, adjusting a first transmission power for the first BS and a second transmission power for the second BS; and

identifying a first power headroom for the first BS and a second power headroom for the second BS based on the first transmission power and the second transmission power.

8. The method of claim 7 , further comprising:

receiving maximum transmission power distribution information of the UE for the first BS and the second BS from at least one of the first BS and the second BS.

9. The method of claim 1 , wherein a first MAC entity of corresponding to the first BS and a second MAC entity corresponding to the second BS are configured in the UE for the dual connectivity.

10. The method of claim 1 , further comprising:

receiving, from the second BS, information regarding resources allocated based on the dual connectivity PHR.

11. An apparatus for a user equipment (UE) in a wireless communication system, the apparatus comprising:

at least one transceiver; and

at least one processor coupled to the at least one transceiver and configured to:

establish a first link with a first base station (BS) and a second link with a second BS, the first BS and the second BS configured in a dual connectivity for the UE, and

in response to identifying that a power headroom report (PHR) trigger event associated with the first BS occurs, transmit a dual connectivity PHR to the second BS,

wherein the dual connectivity PHR comprises a first power headroom (PH) for a cell provided by the first BS and a second PH for a cell provided by the second BS.

12. The apparatus of claim 11 , wherein the dual connectivity PHR is provided by a media access control (MAC) control element (CE).

13. The apparatus of claim 11 , wherein the at least one processor is further configured to:

receive, from one of the first BS and the second BS, a message comprising:

first control information related to the dual connectivity PHR for the first BS, and

second control information related to the dual connectivity PHR for the second BS.

14. The apparatus of claim 13 ,

wherein the first control information comprises a periodic timer, a prohibit timer, and a threshold for a path loss change for the first BS, and

wherein the second control information comprises a periodic timer, a prohibit timer, and a threshold for a path loss change for the second BS.

15. The apparatus of claim 11 , wherein the dual connectivity PHR is transmitted through an uplink resource allocated by the second BS.

16. The apparatus of claim 11 , wherein the at least one processor is further configured to:

identify that the PHR trigger event occurs based on at least one of a path loss change, a maximum power reduction (MPR) change, secondary cell (Scell) activation, Scell addition, and a power back off change.

17. The apparatus of claim 11 , wherein the at least one processor is further configured to:

in response to identifying that the PHR trigger event, adjust a first transmission power for the first BS and a second transmission power for the second BS; and

identifying a first power headroom for the first BS and a second power headroom for the second BS based on the first transmission power and the second transmission power.

18. The apparatus of claim 17 , wherein the at least one processor is further configured to:

receive maximum transmission power distribution information of the UE for the first BS and the second BS from at least one of the first BS and the second BS.

19. The apparatus of claim 11 , wherein a first MAC entity of corresponding to the first BS and a second MAC entity corresponding to the second BS are configured in the UE for the dual connectivity.

20. The apparatus of claim 11 , wherein the at least one processor is further configured to receive, from the second BS, information regarding resources allocated based on the dual connectivity PHR.